/* http://keith-wood.name/countdown.html
Countdown for jQuery v1.5.11.
Written by Keith Wood (kbwood{at}iinet.com.au) January 2008.
Dual licensed under the GPL (http://dev.jquery.com/browser/trunk/jquery/GPL-LICENSE.txt) and 
MIT (http://dev.jquery.com/browser/trunk/jquery/MIT-LICENSE.txt) licenses. 
Please attribute the author if you use it. */

/* Display a countdown timer.
Attach it with options like:
$('div selector').countdown(
{until: new Date(2009, 1 - 1, 1, 0, 0, 0), onExpiry: happyNewYear}); */

(function ($) { // Hide scope, no $ conflict

    /* Countdown manager. */
    function Countdown() {
        this.regional = []; // Available regional settings, indexed by language code
        this.regional[''] = { // Default regional settings
            // The display texts for the counters
            labels: ['Years', 'Months', 'Weeks', 'Days', 'Hours', 'Minutes', 'Seconds'],
            // The display texts for the counters if only one
            labels1: ['Year', 'Month', 'Week', 'Day', 'Hour', 'Minute', 'Second'],
            compactLabels: ['y', 'm', 'w', 'd'], // The compact texts for the counters
            whichLabels: null, // Function to determine which labels to use
            timeSeparator: ':', // Separator for time periods
            isRTL: false // True for right-to-left languages, false for left-to-right
        };
        this._defaults = {
            until: null, // new Date(year, mth - 1, day, hr, min, sec) - date/time to count down to
            // or numeric for seconds offset, or string for unit offset(s):
            // 'Y' years, 'O' months, 'W' weeks, 'D' days, 'H' hours, 'M' minutes, 'S' seconds
            since: null, // new Date(year, mth - 1, day, hr, min, sec) - date/time to count up from
            // or numeric for seconds offset, or string for unit offset(s):
            // 'Y' years, 'O' months, 'W' weeks, 'D' days, 'H' hours, 'M' minutes, 'S' seconds
            timezone: null, // The timezone (hours or minutes from GMT) for the target times,
            // or null for client local
            serverSync: null, // A function to retrieve the current server time for synchronisation
            format: 'dHMS', // Format for display - upper case for always, lower case only if non-zero,
            // 'Y' years, 'O' months, 'W' weeks, 'D' days, 'H' hours, 'M' minutes, 'S' seconds
            layout: '', // Build your own layout for the countdown
            compact: false, // True to display in a compact format, false for an expanded one
            significant: 0, // The number of periods with values to show, zero for all
            description: '', // The description displayed for the countdown
            expiryUrl: '', // A URL to load upon expiry, replacing the current page
            expiryText: '', // Text to display upon expiry, replacing the countdown
            alwaysExpire: false, // True to trigger onExpiry even if never counted down
            onExpiry: null, // Callback when the countdown expires -
            // receives no parameters and 'this' is the containing division
            onTick: null, // Callback when the countdown is updated -
            // receives int[7] being the breakdown by period (based on format)
            // and 'this' is the containing division
            tickInterval: 1 // Interval (seconds) between onTick callbacks
        };
        $.extend(this._defaults, this.regional['']);
        this._serverSyncs = [];
        // Shared timer for all countdowns
        function timerCallBack(timestamp) {
            var drawStart = (timestamp || new Date().getTime());
            if (drawStart - animationStartTime >= 1000) {
                $.countdown._updateTargets();
                animationStartTime = drawStart;
            }
            requestAnimationFrame(timerCallBack);
        }
        var requestAnimationFrame = window.requestAnimationFrame || window.webkitRequestAnimationFrame ||
		window.mozRequestAnimationFrame || window.oRequestAnimationFrame ||
		window.msRequestAnimationFrame || null; // this is when we expect a fall-back to setInterval as it's much more fluid
        var animationStartTime = 0;
        if (!requestAnimationFrame) {
            setInterval(function () { $.countdown._updateTargets(); }, 980); // Fall back to good old setInterval
        }
        else {
            animationStartTime = window.mozAnimationStartTime || new Date().getTime();
            requestAnimationFrame(timerCallBack);
        }
    }

    var PROP_NAME = 'countdown';

    var Y = 0; // Years
    var O = 1; // Months
    var W = 2; // Weeks
    var D = 3; // Days
    var H = 4; // Hours
    var M = 5; // Minutes
    var S = 6; // Seconds

    $.extend(Countdown.prototype, {
        /* Class name added to elements to indicate already configured with countdown. */
        markerClassName: 'hasCountdown',

        /* List of currently active countdown targets. */
        _timerTargets: [],

        /* Override the default settings for all instances of the countdown widget.
        @param  options  (object) the new settings to use as defaults */
        setDefaults: function (options) {
            this._resetExtraLabels(this._defaults, options);
            extendRemove(this._defaults, options || {});
        },

        /* Convert a date/time to UTC.
        @param  tz     (number) the hour or minute offset from GMT, e.g. +9, -360
        @param  year   (Date) the date/time in that timezone or
        (number) the year in that timezone
        @param  month  (number, optional) the month (0 - 11) (omit if year is a Date)
        @param  day    (number, optional) the day (omit if year is a Date)
        @param  hours  (number, optional) the hour (omit if year is a Date)
        @param  mins   (number, optional) the minute (omit if year is a Date)
        @param  secs   (number, optional) the second (omit if year is a Date)
        @param  ms     (number, optional) the millisecond (omit if year is a Date)
        @return  (Date) the equivalent UTC date/time */
        UTCDate: function (tz, year, month, day, hours, mins, secs, ms) {
            if (typeof year == 'object' && year.constructor == Date) {
                ms = year.getMilliseconds();
                secs = year.getSeconds();
                mins = year.getMinutes();
                hours = year.getHours();
                day = year.getDate();
                month = year.getMonth();
                year = year.getFullYear();
            }
            var d = new Date();
            d.setUTCFullYear(year);
            d.setUTCDate(1);
            d.setUTCMonth(month || 0);
            d.setUTCDate(day || 1);
            d.setUTCHours(hours || 0);
            d.setUTCMinutes((mins || 0) - (Math.abs(tz) < 30 ? tz * 60 : tz));
            d.setUTCSeconds(secs || 0);
            d.setUTCMilliseconds(ms || 0);
            return d;
        },

        /* Convert a set of periods into seconds.
        Averaged for months and years.
        @param  periods  (number[7]) the periods per year/month/week/day/hour/minute/second
        @return  (number) the corresponding number of seconds */
        periodsToSeconds: function (periods) {
            return periods[0] * 31557600 + periods[1] * 2629800 + periods[2] * 604800 +
			periods[3] * 86400 + periods[4] * 3600 + periods[5] * 60 + periods[6];
        },

        /* Retrieve one or more settings values.
        @param  name  (string, optional) the name of the setting to retrieve
        or 'all' for all instance settings or omit for all default settings
        @return  (any) the requested setting(s) */
        _settingsCountdown: function (target, name) {
            if (!name) {
                return $.countdown._defaults;
            }
            var inst = $.data(target, PROP_NAME);
            return (name == 'all' ? inst.options : inst.options[name]);
        },

        /* Attach the countdown widget to a div.
        @param  target   (element) the containing division
        @param  options  (object) the initial settings for the countdown */
        _attachCountdown: function (target, options) {
            var $target = $(target);
            if ($target.hasClass(this.markerClassName)) {
                return;
            }
            $target.addClass(this.markerClassName);
            var inst = { options: $.extend({}, options),
                _periods: [0, 0, 0, 0, 0, 0, 0]
            };
            $.data(target, PROP_NAME, inst);
            this._changeCountdown(target);
        },

        /* Add a target to the list of active ones.
        @param  target  (element) the countdown target */
        _addTarget: function (target) {
            if (!this._hasTarget(target)) {
                this._timerTargets.push(target);
            }
        },

        /* See if a target is in the list of active ones.
        @param  target  (element) the countdown target
        @return  (boolean) true if present, false if not */
        _hasTarget: function (target) {
            return ($.inArray(target, this._timerTargets) > -1);
        },

        /* Remove a target from the list of active ones.
        @param  target  (element) the countdown target */
        _removeTarget: function (target) {
            this._timerTargets = $.map(this._timerTargets,
			function (value) { return (value == target ? null : value); }); // delete entry
        },

        /* Update each active timer target. */
        _updateTargets: function () {
            for (var i = this._timerTargets.length - 1; i >= 0; i--) {
                this._updateCountdown(this._timerTargets[i]);
            }
        },

        /* Redisplay the countdown with an updated display.
        @param  target  (jQuery) the containing division
        @param  inst    (object) the current settings for this instance */
        _updateCountdown: function (target, inst) {
            var $target = $(target);
            inst = inst || $.data(target, PROP_NAME);
            if (!inst) {
                return;
            }
            $target.html(this._generateHTML(inst));
            $target[(this._get(inst, 'isRTL') ? 'add' : 'remove') + 'Class']('countdown_rtl');
            var onTick = this._get(inst, 'onTick');
            if (onTick) {
                var periods = inst._hold != 'lap' ? inst._periods :
				this._calculatePeriods(inst, inst._show, this._get(inst, 'significant'), new Date());
                var tickInterval = this._get(inst, 'tickInterval');
                if (tickInterval == 1 || this.periodsToSeconds(periods) % tickInterval == 0) {
                    onTick.apply(target, [periods]);
                }
            }
            var expired = inst._hold != 'pause' &&
			(inst._since ? inst._now.getTime() < inst._since.getTime() :
			inst._now.getTime() >= inst._until.getTime());
            if (expired && !inst._expiring) {
                inst._expiring = true;
                if (this._hasTarget(target) || this._get(inst, 'alwaysExpire')) {
                    this._removeTarget(target);
                    var onExpiry = this._get(inst, 'onExpiry');
                    if (onExpiry) {
                        onExpiry.apply(target, []);
                    }
                    var expiryText = this._get(inst, 'expiryText');
                    if (expiryText) {
                        var layout = this._get(inst, 'layout');
                        inst.options.layout = expiryText;
                        this._updateCountdown(target, inst);
                        inst.options.layout = layout;
                    }
                    var expiryUrl = this._get(inst, 'expiryUrl');
                    if (expiryUrl) {
                        window.location = expiryUrl;
                    }
                }
                inst._expiring = false;
            }
            else if (inst._hold == 'pause') {
                this._removeTarget(target);
            }
            $.data(target, PROP_NAME, inst);
        },

        /* Reconfigure the settings for a countdown div.
        @param  target   (element) the containing division
        @param  options  (object) the new settings for the countdown or
        (string) an individual property name
        @param  value    (any) the individual property value
        (omit if options is an object) */
        _changeCountdown: function (target, options, value) {
            options = options || {};
            if (typeof options == 'string') {
                var name = options;
                options = {};
                options[name] = value;
            }
            var inst = $.data(target, PROP_NAME);
            if (inst) {
                this._resetExtraLabels(inst.options, options);
                extendRemove(inst.options, options);
                this._adjustSettings(target, inst);
                $.data(target, PROP_NAME, inst);
                var now = new Date();
                if ((inst._since && inst._since < now) ||
					(inst._until && inst._until > now)) {
                    this._addTarget(target);
                }
                this._updateCountdown(target, inst);
            }
        },

        /* Reset any extra labelsn and compactLabelsn entries if changing labels.
        @param  base     (object) the options to be updated
        @param  options  (object) the new option values */
        _resetExtraLabels: function (base, options) {
            var changingLabels = false;
            for (var n in options) {
                if (n != 'whichLabels' && n.match(/[Ll]abels/)) {
                    changingLabels = true;
                    break;
                }
            }
            if (changingLabels) {
                for (var n in base) { // Remove custom numbered labels
                    if (n.match(/[Ll]abels[0-9]/)) {
                        base[n] = null;
                    }
                }
            }
        },

        /* Calculate interal settings for an instance.
        @param  target  (element) the containing division
        @param  inst    (object) the current settings for this instance */
        _adjustSettings: function (target, inst) {
            var now;
            var serverSync = this._get(inst, 'serverSync');
            var serverOffset = 0;
            var serverEntry = null;
            for (var i = 0; i < this._serverSyncs.length; i++) {
                if (this._serverSyncs[i][0] == serverSync) {
                    serverEntry = this._serverSyncs[i][1];
                    break;
                }
            }
            if (serverEntry != null) {
                serverOffset = (serverSync ? serverEntry : 0);
                now = new Date();
            }
            else {
                var serverResult = (serverSync ? serverSync.apply(target, []) : null);
                now = new Date();
                serverOffset = (serverResult ? now.getTime() - serverResult.getTime() : 0);
                this._serverSyncs.push([serverSync, serverOffset]);
            }
            var timezone = this._get(inst, 'timezone');
            timezone = (timezone == null ? -now.getTimezoneOffset() : timezone);
            inst._since = this._get(inst, 'since');
            if (inst._since != null) {
                inst._since = this.UTCDate(timezone, this._determineTime(inst._since, null));
                if (inst._since && serverOffset) {
                    inst._since.setMilliseconds(inst._since.getMilliseconds() + serverOffset);
                }
            }
            inst._until = this.UTCDate(timezone, this._determineTime(this._get(inst, 'until'), now));
            if (serverOffset) {
                inst._until.setMilliseconds(inst._until.getMilliseconds() + serverOffset);
            }
            inst._show = this._determineShow(inst);
        },

        /* Remove the countdown widget from a div.
        @param  target  (element) the containing division */
        _destroyCountdown: function (target) {
            var $target = $(target);
            if (!$target.hasClass(this.markerClassName)) {
                return;
            }
            this._removeTarget(target);
            $target.removeClass(this.markerClassName).empty();
            $.removeData(target, PROP_NAME);
        },

        /* Pause a countdown widget at the current time.
        Stop it running but remember and display the current time.
        @param  target  (element) the containing division */
        _pauseCountdown: function (target) {
            this._hold(target, 'pause');
        },

        /* Pause a countdown widget at the current time.
        Stop the display but keep the countdown running.
        @param  target  (element) the containing division */
        _lapCountdown: function (target) {
            this._hold(target, 'lap');
        },

        /* Resume a paused countdown widget.
        @param  target  (element) the containing division */
        _resumeCountdown: function (target) {
            this._hold(target, null);
        },

        /* Pause or resume a countdown widget.
        @param  target  (element) the containing division
        @param  hold    (string) the new hold setting */
        _hold: function (target, hold) {
            var inst = $.data(target, PROP_NAME);
            if (inst) {
                if (inst._hold == 'pause' && !hold) {
                    inst._periods = inst._savePeriods;
                    var sign = (inst._since ? '-' : '+');
                    inst[inst._since ? '_since' : '_until'] =
					this._determineTime(sign + inst._periods[0] + 'y' +
						sign + inst._periods[1] + 'o' + sign + inst._periods[2] + 'w' +
						sign + inst._periods[3] + 'd' + sign + inst._periods[4] + 'h' +
						sign + inst._periods[5] + 'm' + sign + inst._periods[6] + 's');
                    this._addTarget(target);
                }
                inst._hold = hold;
                inst._savePeriods = (hold == 'pause' ? inst._periods : null);
                $.data(target, PROP_NAME, inst);
                this._updateCountdown(target, inst);
            }
        },

        /* Return the current time periods.
        @param  target  (element) the containing division
        @return  (number[7]) the current periods for the countdown */
        _getTimesCountdown: function (target) {
            var inst = $.data(target, PROP_NAME);
            return (!inst ? null : (!inst._hold ? inst._periods :
			this._calculatePeriods(inst, inst._show, this._get(inst, 'significant'), new Date())));
        },

        /* Get a setting value, defaulting if necessary.
        @param  inst  (object) the current settings for this instance
        @param  name  (string) the name of the required setting
        @return  (any) the setting's value or a default if not overridden */
        _get: function (inst, name) {
            return (inst.options[name] != null ?
			inst.options[name] : $.countdown._defaults[name]);
        },

        /* A time may be specified as an exact value or a relative one.
        @param  setting      (string or number or Date) - the date/time value
        as a relative or absolute value
        @param  defaultTime  (Date) the date/time to use if no other is supplied
        @return  (Date) the corresponding date/time */
        _determineTime: function (setting, defaultTime) {
            var offsetNumeric = function (offset) { // e.g. +300, -2
                var time = new Date();
                time.setTime(time.getTime() + offset * 1000);
                return time;
            };
            var offsetString = function (offset) { // e.g. '+2d', '-4w', '+3h +30m'
                offset = offset.toLowerCase();
                var time = new Date();
                var year = time.getFullYear();
                var month = time.getMonth();
                var day = time.getDate();
                var hour = time.getHours();
                var minute = time.getMinutes();
                var second = time.getSeconds();
                var pattern = /([+-]?[0-9]+)\s*(s|m|h|d|w|o|y)?/g;
                var matches = pattern.exec(offset);
                while (matches) {
                    switch (matches[2] || 's') {
                        case 's': second += parseInt(matches[1], 10); break;
                        case 'm': minute += parseInt(matches[1], 10); break;
                        case 'h': hour += parseInt(matches[1], 10); break;
                        case 'd': day += parseInt(matches[1], 10); break;
                        case 'w': day += parseInt(matches[1], 10) * 7; break;
                        case 'o':
                            month += parseInt(matches[1], 10);
                            day = Math.min(day, $.countdown._getDaysInMonth(year, month));
                            break;
                        case 'y':
                            year += parseInt(matches[1], 10);
                            day = Math.min(day, $.countdown._getDaysInMonth(year, month));
                            break;
                    }
                    matches = pattern.exec(offset);
                }
                return new Date(year, month, day, hour, minute, second, 0);
            };
            var time = (setting == null ? defaultTime :
			(typeof setting == 'string' ? offsetString(setting) :
			(typeof setting == 'number' ? offsetNumeric(setting) : setting)));
            if (time) time.setMilliseconds(0);
            return time;
        },

        /* Determine the number of days in a month.
        @param  year   (number) the year
        @param  month  (number) the month
        @return  (number) the days in that month */
        _getDaysInMonth: function (year, month) {
            return 32 - new Date(year, month, 32).getDate();
        },

        /* Determine which set of labels should be used for an amount.
        @param  num  (number) the amount to be displayed
        @return  (number) the set of labels to be used for this amount */
        _normalLabels: function (num) {
            return num;
        },

        /* Generate the HTML to display the countdown widget.
        @param  inst  (object) the current settings for this instance
        @return  (string) the new HTML for the countdown display */
        _generateHTML: function (inst) {
            // Determine what to show
            var significant = this._get(inst, 'significant');
            inst._periods = (inst._hold ? inst._periods :
			this._calculatePeriods(inst, inst._show, significant, new Date()));
            // Show all 'asNeeded' after first non-zero value
            var shownNonZero = false;
            var showCount = 0;
            var sigCount = significant;
            var show = $.extend({}, inst._show);
            for (var period = Y; period <= S; period++) {
                shownNonZero |= (inst._show[period] == '?' && inst._periods[period] > 0);
                show[period] = (inst._show[period] == '?' && !shownNonZero ? null : inst._show[period]);
                showCount += (show[period] ? 1 : 0);
                sigCount -= (inst._periods[period] > 0 ? 1 : 0);
            }
            var showSignificant = [false, false, false, false, false, false, false];
            for (var period = S; period >= Y; period--) { // Determine significant periods
                if (inst._show[period]) {
                    if (inst._periods[period]) {
                        showSignificant[period] = true;
                    }
                    else {
                        showSignificant[period] = sigCount > 0;
                        sigCount--;
                    }
                }
            }
            var compact = this._get(inst, 'compact');
            var layout = this._get(inst, 'layout');
            var labels = (compact ? this._get(inst, 'compactLabels') : this._get(inst, 'labels'));
            var whichLabels = this._get(inst, 'whichLabels') || this._normalLabels;
            var timeSeparator = this._get(inst, 'timeSeparator');
            var description = this._get(inst, 'description') || '';
            var showCompact = function (period) {
                var labelsNum = $.countdown._get(inst,
				'compactLabels' + whichLabels(inst._periods[period]));
                return (show[period] ? inst._periods[period] +
				(labelsNum ? labelsNum[period] : labels[period]) + ' ' : '');
            };
            var showFull = function (period) {
                var labelsNum = $.countdown._get(inst, 'labels' + whichLabels(inst._periods[period]));
                return ((!significant && show[period]) || (significant && showSignificant[period]) ?
				'<span class="countdown_section"><span class="countdown_amount">' +
				inst._periods[period] + '</span><br/>' +
				(labelsNum ? labelsNum[period] : labels[period]) + '</span>' : '');
            };
            return (layout ? this._buildLayout(inst, show, layout, compact, significant, showSignificant) :
			((compact ? // Compact version
			'<span class="countdown_row countdown_amount' +
			(inst._hold ? ' countdown_holding' : '') + '">' +
			showCompact(Y) + showCompact(O) + showCompact(W) + showCompact(D) +
			(show[H] ? this._minDigits(inst._periods[H], 2) : '') +
			(show[M] ? (show[H] ? timeSeparator : '') +
			this._minDigits(inst._periods[M], 2) : '') +
			(show[S] ? (show[H] || show[M] ? timeSeparator : '') +
			this._minDigits(inst._periods[S], 2) : '') :
            // Full version
			'<span class="countdown_row countdown_show' + (significant || showCount) +
			(inst._hold ? ' countdown_holding' : '') + '">' +
			showFull(Y) + showFull(O) + showFull(W) + showFull(D) +
			showFull(H) + showFull(M) + showFull(S)) + '</span>' +
			(description ? '<span class="countdown_row countdown_descr">' + description + '</span>' : '')));
        },

        /* Construct a custom layout.
        @param  inst             (object) the current settings for this instance
        @param  show             (string[7]) flags indicating which periods are requested
        @param  layout           (string) the customised layout
        @param  compact          (boolean) true if using compact labels
        @param  significant      (number) the number of periods with values to show, zero for all
        @param  showSignificant  (boolean[7]) other periods to show for significance
        @return  (string) the custom HTML */
        _buildLayout: function (inst, show, layout, compact, significant, showSignificant) {
            var labels = this._get(inst, (compact ? 'compactLabels' : 'labels'));
            var whichLabels = this._get(inst, 'whichLabels') || this._normalLabels;
            var labelFor = function (index) {
                return ($.countdown._get(inst,
				(compact ? 'compactLabels' : 'labels') + whichLabels(inst._periods[index])) ||
				labels)[index];
            };
            var digit = function (value, position) {
                return Math.floor(value / position) % 10;
            };
            var subs = { desc: this._get(inst, 'description'), sep: this._get(inst, 'timeSeparator'),
                yl: labelFor(Y), yn: inst._periods[Y], ynn: this._minDigits(inst._periods[Y], 2),
                ynnn: this._minDigits(inst._periods[Y], 3), y1: digit(inst._periods[Y], 1),
                y10: digit(inst._periods[Y], 10), y100: digit(inst._periods[Y], 100),
                y1000: digit(inst._periods[Y], 1000),
                ol: labelFor(O), on: inst._periods[O], onn: this._minDigits(inst._periods[O], 2),
                onnn: this._minDigits(inst._periods[O], 3), o1: digit(inst._periods[O], 1),
                o10: digit(inst._periods[O], 10), o100: digit(inst._periods[O], 100),
                o1000: digit(inst._periods[O], 1000),
                wl: labelFor(W), wn: inst._periods[W], wnn: this._minDigits(inst._periods[W], 2),
                wnnn: this._minDigits(inst._periods[W], 3), w1: digit(inst._periods[W], 1),
                w10: digit(inst._periods[W], 10), w100: digit(inst._periods[W], 100),
                w1000: digit(inst._periods[W], 1000),
                dl: labelFor(D), dn: inst._periods[D], dnn: this._minDigits(inst._periods[D], 2),
                dnnn: this._minDigits(inst._periods[D], 3), d1: digit(inst._periods[D], 1),
                d10: digit(inst._periods[D], 10), d100: digit(inst._periods[D], 100),
                d1000: digit(inst._periods[D], 1000),
                hl: labelFor(H), hn: inst._periods[H], hnn: this._minDigits(inst._periods[H], 2),
                hnnn: this._minDigits(inst._periods[H], 3), h1: digit(inst._periods[H], 1),
                h10: digit(inst._periods[H], 10), h100: digit(inst._periods[H], 100),
                h1000: digit(inst._periods[H], 1000),
                ml: labelFor(M), mn: inst._periods[M], mnn: this._minDigits(inst._periods[M], 2),
                mnnn: this._minDigits(inst._periods[M], 3), m1: digit(inst._periods[M], 1),
                m10: digit(inst._periods[M], 10), m100: digit(inst._periods[M], 100),
                m1000: digit(inst._periods[M], 1000),
                sl: labelFor(S), sn: inst._periods[S], snn: this._minDigits(inst._periods[S], 2),
                snnn: this._minDigits(inst._periods[S], 3), s1: digit(inst._periods[S], 1),
                s10: digit(inst._periods[S], 10), s100: digit(inst._periods[S], 100),
                s1000: digit(inst._periods[S], 1000)
            };
            var html = layout;
            // Replace period containers: {p<}...{p>}
            for (var i = Y; i <= S; i++) {
                var period = 'yowdhms'.charAt(i);
                var re = new RegExp('\\{' + period + '<\\}(.*)\\{' + period + '>\\}', 'g');
                html = html.replace(re, ((!significant && show[i]) ||
				(significant && showSignificant[i]) ? '$1' : ''));
            }
            // Replace period values: {pn}
            $.each(subs, function (n, v) {
                var re = new RegExp('\\{' + n + '\\}', 'g');
                html = html.replace(re, v);
            });
            return html;
        },

        /* Ensure a numeric value has at least n digits for display.
        @param  value  (number) the value to display
        @param  len    (number) the minimum length
        @return  (string) the display text */
        _minDigits: function (value, len) {
            value = '' + value;
            if (value.length >= len) {
                return value;
            }
            value = '0000000000' + value;
            return value.substr(value.length - len);
        },

        /* Translate the format into flags for each period.
        @param  inst  (object) the current settings for this instance
        @return  (string[7]) flags indicating which periods are requested (?) or
        required (!) by year, month, week, day, hour, minute, second */
        _determineShow: function (inst) {
            var format = this._get(inst, 'format');
            var show = [];
            show[Y] = (format.match('y') ? '?' : (format.match('Y') ? '!' : null));
            show[O] = (format.match('o') ? '?' : (format.match('O') ? '!' : null));
            show[W] = (format.match('w') ? '?' : (format.match('W') ? '!' : null));
            show[D] = (format.match('d') ? '?' : (format.match('D') ? '!' : null));
            show[H] = (format.match('h') ? '?' : (format.match('H') ? '!' : null));
            show[M] = (format.match('m') ? '?' : (format.match('M') ? '!' : null));
            show[S] = (format.match('s') ? '?' : (format.match('S') ? '!' : null));
            return show;
        },

        /* Calculate the requested periods between now and the target time.
        @param  inst         (object) the current settings for this instance
        @param  show         (string[7]) flags indicating which periods are requested/required
        @param  significant  (number) the number of periods with values to show, zero for all
        @param  now          (Date) the current date and time
        @return  (number[7]) the current time periods (always positive)
        by year, month, week, day, hour, minute, second */
        _calculatePeriods: function (inst, show, significant, now) {
            // Find endpoints
            inst._now = now;
            inst._now.setMilliseconds(0);
            var until = new Date(inst._now.getTime());
            if (inst._since) {
                if (now.getTime() < inst._since.getTime()) {
                    inst._now = now = until;
                }
                else {
                    now = inst._since;
                }
            }
            else {
                until.setTime(inst._until.getTime());
                if (now.getTime() > inst._until.getTime()) {
                    inst._now = now = until;
                }
            }
            // Calculate differences by period
            var periods = [0, 0, 0, 0, 0, 0, 0];
            if (show[Y] || show[O]) {
                // Treat end of months as the same
                var lastNow = $.countdown._getDaysInMonth(now.getFullYear(), now.getMonth());
                var lastUntil = $.countdown._getDaysInMonth(until.getFullYear(), until.getMonth());
                var sameDay = (until.getDate() == now.getDate() ||
				(until.getDate() >= Math.min(lastNow, lastUntil) &&
				now.getDate() >= Math.min(lastNow, lastUntil)));
                var getSecs = function (date) {
                    return (date.getHours() * 60 + date.getMinutes()) * 60 + date.getSeconds();
                };
                var months = Math.max(0,
				(until.getFullYear() - now.getFullYear()) * 12 + until.getMonth() - now.getMonth() +
				((until.getDate() < now.getDate() && !sameDay) ||
				(sameDay && getSecs(until) < getSecs(now)) ? -1 : 0));
                periods[Y] = (show[Y] ? Math.floor(months / 12) : 0);
                periods[O] = (show[O] ? months - periods[Y] * 12 : 0);
                // Adjust for months difference and end of month if necessary
                now = new Date(now.getTime());
                var wasLastDay = (now.getDate() == lastNow);
                var lastDay = $.countdown._getDaysInMonth(now.getFullYear() + periods[Y],
				now.getMonth() + periods[O]);
                if (now.getDate() > lastDay) {
                    now.setDate(lastDay);
                }
                now.setFullYear(now.getFullYear() + periods[Y]);
                now.setMonth(now.getMonth() + periods[O]);
                if (wasLastDay) {
                    now.setDate(lastDay);
                }
            }
            var diff = Math.floor((until.getTime() - now.getTime()) / 1000);
            var extractPeriod = function (period, numSecs) {
                periods[period] = (show[period] ? Math.floor(diff / numSecs) : 0);
                diff -= periods[period] * numSecs;
            };
            extractPeriod(W, 604800);
            extractPeriod(D, 86400);
            extractPeriod(H, 3600);
            extractPeriod(M, 60);
            extractPeriod(S, 1);
            if (diff > 0 && !inst._since) { // Round up if left overs
                var multiplier = [1, 12, 4.3482, 7, 24, 60, 60];
                var lastShown = S;
                var max = 1;
                for (var period = S; period >= Y; period--) {
                    if (show[period]) {
                        if (periods[lastShown] >= max) {
                            periods[lastShown] = 0;
                            diff = 1;
                        }
                        if (diff > 0) {
                            periods[period]++;
                            diff = 0;
                            lastShown = period;
                            max = 1;
                        }
                    }
                    max *= multiplier[period];
                }
            }
            if (significant) { // Zero out insignificant periods
                for (var period = Y; period <= S; period++) {
                    if (significant && periods[period]) {
                        significant--;
                    }
                    else if (!significant) {
                        periods[period] = 0;
                    }
                }
            }
            return periods;
        }
    });

    /* jQuery extend now ignores nulls!
    @param  target  (object) the object to update
    @param  props   (object) the new settings
    @return  (object) the updated object */
    function extendRemove(target, props) {
        $.extend(target, props);
        for (var name in props) {
            if (props[name] == null) {
                target[name] = null;
            }
        }
        return target;
    }

    /* Process the countdown functionality for a jQuery selection.
    @param  command  (string) the command to run (optional, default 'attach')
    @param  options  (object) the new settings to use for these countdown instances
    @return  (jQuery) for chaining further calls */
    $.fn.countdown = function (options) {
        var otherArgs = Array.prototype.slice.call(arguments, 1);
        if (options == 'getTimes' || options == 'settings') {
            return $.countdown['_' + options + 'Countdown'].
			apply($.countdown, [this[0]].concat(otherArgs));
        }
        return this.each(function () {
            if (typeof options == 'string') {
                $.countdown['_' + options + 'Countdown'].apply($.countdown, [this].concat(otherArgs));
            }
            else {
                $.countdown._attachCountdown(this, options);
            }
        });
    };

    /* Initialise the countdown functionality. */
    $.countdown = new Countdown(); // singleton instance

})(jQuery);
